Hydraulic-elevator safety device.



T. E'. BROWN. HYDRAULIC ELEVATOR SAFETY DEVICE.

APPLICATION FILED NOV. 23, 1905.

Patented June 4, 1912.

MNM JT- ...n'mlmfl 1 THOMAS E. BROWN, 0F NEW YORK, N1 Yi,

JERsEY CITY, NEW JERSEY,

HYnRAULI'c-EEEVATOR SAFETY DEVICE.

Application filed November '23, 1905.

Specicaton of Letters Patent;

AssIGNOR To OTIs ELEvAToR COMPANY, OF A CORPORATION OE vNEW JERSEY.

Patented J une 4, 1912. semi No. 288,637.

To all. whom 'it may concern: y

Be it known that I, THOMAS E. BROWN, a citizen of the United St-ates,residing at New York city, in the county of New York and State of NewYork, have invented a new and useful Improvement in I-Iydraulic-Elevator Safety Devices, of which the following is a specification.

My invention relates to safety devices for elevators of the plungertype.

One of the objects of my invention is the provision of simple andefficient means for` retarding the speed of a plunger elevator' car whenthe same moves too rapidly. y

More particularly it is the object of the present invention to provide adevice which will prevent the descent of the elevatorcar at a speedbeyond that which may be predetermined under any conditions whatsoever,other than the bursting of the cylinder itself, or the collapsing of theplunger.

Other objects of the invention will appear hereinafter, the novelcombinations of elements being pointed out inthe claims.

In the accompanying drawings, Figure 1 represents a plunger elevatorsystem in elevation with my invention applied thereto; and Fig. 2 is anenlarged sectional elevation of my invention showing the detailsthereof.

In Fig. 1 is shown a plunger elevator system of usual constructioncomprising a car C, counterweight 1, counterweight sheave '2, on theoverhead beam 4, counterweight cable 3, change valve 5 with its supplyport 6 and exhaust port 7, means 8 for operating the change valve, aplunger 9A and a cylinder 10.

rIhe upper section 11 of the plunger cylinder is enlarged in diameterand is preferably, though not necessarily, provided with a brass orbronze liner 12, the inlet and outlet port 27 is at one side of thissection and is connected by the pipe 13 to the change valve 5. The port27 may communicate with the plunger cylinder directly, but I prefer tocarry an annular port 14 around the cylinder section and connect withthe interior by the graduated or restricted perforations or openings inthe liner 12. In this instance I have shown the inlet and outlet port27, the annu -ar port 14 and the perforations 15 in the liner 12 inalinement with each ot-her and near the upper portion of the cylindersection 11.

16 designates a heavy ring or cylinder of metal which fits looselywithin the liner 12 so as to be free to move up and down. Each end ofthe ring is provided with an inwardly extending flange but annularspaces 17, 17 are left between said flanges and the plunger, and anannular space 1.8 is left between the body of the ring and the plunger.If desired the flanges may be omitted.

Under normal conditions of operation the ring 16 rests on a plurality oflugs 19 which extend upwardly from the iiange 20. When the car and itsplunger are ascending the ring 16 rests on the lugs 19, and the [motorfluid passes from the inlet port 27 through the perforations 15 in theliner 12 and thence down through the annular space between the ring 16and the plunger to the underside of the plunger. Since in this case t-hepressure on top of the ring is always as great or slightly greater thanthe pressure on the bottom of the ring, the ring will remain at rest onthe lugs 19.

When the car and its plunger descend the motor fluid will pass from thecylinder 10 up through the annular space between the ring 16 and theplunger and out to the change valve exhaust-port through theperforations 15 in the liner 12. Now it is evident that when the annularspace 18, the pressure on the bottom of the ring 16 will be greater thanthe pressure on the top of the ring 16 by an amount equal to the losslof head, due to the velocity of water in the annular space. Hence theconditions of equilibrium require that since the top and bottom areas ofthe ring are substantially the same, the pressure on the bottom of thering must be equal t0 the pressure on the top of the ring, weight of thering its lf. rAnyexcess, therefore, of' the pressure on the .bottom ofthe ring over the pressureon the top of the ring greater than the weightof the ring, must cause the ring to moveV upwardly, until, by throttlingthe holes 15 linthe-liner 12, the

equilibrium is againestablished by raising,

the pressure above the ring 4until it is equal to the pressure under thering less an amount equal to the weightof the ring. It will thus be seenthat the difference of `pressure above andv below ,the ring must be thatdue to the weight of the ringV itself, or a constant quantity. Now, asthe annular the water ascends through plus the space is fixed, and thedifference of pressure at the top and bottom of the ring must be thehydraulic loss in the annular space, and as above demonstrated, thismust be a constant, and correspond to the weight of the ring, it isevident that the velocity Athrough the annular space cannot exceed thatdue to the hydraulic head corresponding to the Weight of the ring.Therefore, no matter what the conditions may be, such as the breaking ofthe discharge pipe, or loss of control of the apparatus in any way, thedescending speed of the plunger being directly proportional to thevelocity of the waterthrough the annular space, cannot exceed thevelocity due to the difference of.

hydraulic head corresponding` to the weight of the ring 16.v

I prefer, for the sake of accuracy, to rely entirely upon the weight ofthe annular ring 16 for this difference of head, but there may be caseswhere it would be inconvenient or undesirable to make the ring` 16 ofsufficient weight to account for the full difference of pressuredesired. In such cases one or more springs, such as indicated at 21, maybe inserted and retained in position in any suitable manner. In thisinstance, I have shown a holder 22 secured to the under side of thecylinder head 23, and a corresponding movable holder 24 for the lowerend of the' spring. The lower holder is pro-vided with a `stem 25 whichextends downwardly and engages the upper annular surface of the ring 16.The stern 25 is guided by a perforation in the partition 26. The effectof such springs is equivalent to an increased weight of the ring 16, solong as the springs are of such length that the change of strain due totheir compression by the rising of the weight, is not material. If,however, made of such length, then the action of the apparatiis will beonly approximate. Other equivalents of a spring may be used if desired,such as weights acting on levers connected to the ring 16 throughstuffing boxes. Y

It will be evident that the ring 16 may be made to lit the plunger, andthat the equivalent of the annular space may be obtainedl by holesthrough the ring, but I prefer the method of construction shown. Also,the apparatus may be made adjustable by providing means of changing thesize of the annular space, or the equivalent holes through the ring, butI prefer to construct the apparatus without such adjustment, as Iconsider it better to determine the hydraulic coefficient of the annularspace and give it a proper size to begin with. It will also be evidentthat with a given size of the annular space, and a given coeliicient ofhydraulic friction, the greater the weight 16, the greater the speed,and vice' versa.

the springs are not v Hence where springs or other equivalents are used,the speed may be varied by adjusting such springs, or their equivalents.

In the remote contingency of the cylinder head blowing oft', theapparatus described wouldv not operate to retard the speed of thedescending car `but on the contrary would alloW thesame to lower itselfvery rapidly. I therefore secure to the lining 12 above theperforations, a stop which in this instance I have shown in the form ofa ring 26. The ring will then perform the same function whether thecylinder head 23 is on or not. The ring 26 serves also as a partition toform a chamber for the springs, such as that designated 21. When t-hecylinder head is off, the springs cannot of course, .act to increase ineffect the weight of the ring, but the release of the springs will causetheA perforations 15 to be throttled more quickly and completely andtherefore all the more retard the downward travel of the car.

`Many variations and changes in the details of construction andarrangement of parts would readily suggest themselves to those skilledin the art, and still be within the spirit and scope of my invention. Idesire, therefore, not to be limited or restricted to the particularform of construction and arrangement of devices herein shown anddescribed. It is also obvious that the associated operating parts may bevaried, altered, and changed in the details of their yconstruction andarrangement without affecting the principles of my invention.

Having thus set forth the object and nature of my invention, and anoperative embodiment of the principles thereof, what I claim and desireto have protected by Letters Patent of the United States is n 1. In ahydraulic elevator; the combination wit-h a car and plunger, or acylinder for said plunger, and a throttling device within said cylinderarranged to leave an annular space between the plunger and saidthrottling device, the operation of the latter to regulate the outflowof iuid being dependent upon the dierence of pressure ofv the motor Huidexerted on its ends and also upon the weight of its movable part.

2. In a hydraulic elevator, the combination with a car, plunger andcylinder, a throttling device for regulating the outflow of motor fluid,and a partition within the cylinder above the throttling device.

3. In a hydraulic elevator, the combination with a car, plunger andcylinder, of means for controlling the iow of motor fluid to and. fromsaid cylinder, means within said cylinder for limiting the speed o-fdescent of said car, and means for assisting gravity in holding themovable part of said speed-limiting means'normally in its lowermostposition.

i said throttling device normally in its lower-V 4. In a hydraulicelevator, the combination with a car, plunger and cylinder, of athrottling device including a movable part 'carried within said cylinderand acting to regulate the speed of outflow of the motor fluid, and oneor more resilient devices for assisting gravity in holding the movablepart of said throttling device normally in its lowermost position.

5. In a hydraulic elevator, the combination with a car, plunger andcylinder, of a supply pipe connected toy the cylinder, a throttlingdevice carried by said cylinder independently of the supply pipe andacting to regulate the speed of outflow of the fluid, and oneor moreresilient devices for assisting gravity in holding the movable part ofmost position.

6. In a hydraulic elevator, tion with a car, of a plunger and acylinder, and a freely movable cylinder within the hydraulic cylinderfor throttling the outflow of' fluid from said hydraulic cylinderthrough a series of perforations.

7. In a hydraulic elevator, the combination with a car, plunger andcylinder, and a throttling device within said cylinder, said throttlingdevice being constructed and arranged to be dependent upon the weight ofits movable part, and difference of hydraulic head for its operation toregulate thespeed of the motor fluid in said cylinder.

8. In a hydraulic elevator, the combination with a car, plunger andcylinder, of a lining in an enlarged port-ion of said cylinder saidlining having a plurality of perforations establishing communicationbetween said cylinder and an inlet and outlet port, a cylinder movablein said enlarged portion to close one or more of said perforations, apartition above said perforations, and springs between said partitionand the cylinder head, and means acted upon by said springs to exert apressure on the upper end of said movable cylinder.

9. In a plunger elevator bination of the casing, movable therein, a caron the upper end of the plunger, and a governor device for regulatingthe mo-tion of' the car controlled by the pressure to the casing, saidgovernor device being mounted within the plunger casing, the latterbeing constructed and arranged to receive the same.

10. In a plunger elevator system the combination of` the plunger casing,a plunger vertically movable therein, a car on the upper end of theplunger, a to-and-from pipe opening into the plunger casing, and athrottling device located inside the plunger casing, and actuated byfluctuations of pressure thereto for throttling the passage of thetoand-from pipe.

11. In a hydraulic elevator,

system, the comthe combinathe combinaa plunger vertically tion with acar and its plunger, of a receiving cylinder for said plunger, and aninterior cylinder freely movable for throttling the outflow of fluidfrom said cylinder.

12. The combination with a main elevator cylinder, of a plunger in saidcylinder, a valve in said cylinder for controlling the outflow of fluidthrough a port in said cylinder, and pressure-controlled means foroperating said valve.

13. In an elevator, the combination with a car and its plunger, ofa-cylinder, means for controlling the flow of motor-fluid to and fromsaid cylinder, means within said cylinder for limiting the speed ofdescent of the car, and means dependent upon gravity for holding theymovable part of said speed-limiting means normally in its lowermostposition.

14. In a hydraulic elevator, the combination with a car and a plunger,of a cylinder' for said plunger, and a cylindrical throttling deviceloosely surrounding the plunger for regulating the outflow of motorfluid to limit the speed of descent of the car.

15. 'In a hydraulic elevator, the combination with a car and a plunger,of a cylinder for said plunger, means for controlling the flo-w of fluidto and from said cylinder, and a throttling device within said cylinderarranged to leave an annular space between the plunger and saidthrottling device, the operation of the latter to regulate the outflowof fluid being dependent upon difference of pressure of the motor-fluidexerted on its ends and also upon the weight of its movable part.

16. In a hydraulic elevator, the combination with a car, plunger andcylinder, of a throttling device, including a movable part within saidcylinder and acting to regulate the speed of outflow of the motor-fluid,and means for assisting the weight of the movable part of saidthrottling device in holding the said part normally in its lowermostposition.

17. In a hydraulic elevator, the combination with a car, plunger andcylinder, of a supply pipe connected to the cylinder, a throttlingdevice carried by said cylinder independently of the supply pipe andyacting to regulate the speed of outflow of the fluid, and one or moredevices for assisting the weight'of the movable part of said throttlingdevice in holding said part `in its lowermost position.

18. In a hydraulic elevator, the combination with a car, of a plungerand a cylinder, a freely movable cylindrical device within the hydrauliccylinder, and means co-acting with said cylindrical device forthrottling the outflow of fluid from said hydraulic cylinder.

19. In a hydraulic elevator, tion of a car, plunger and cylinder,

vcally movable therein,

throttling device within said cylinder, said throttling device beingconstructed and arranged to be dependent upon the weight of its movablepart and the rate of outflow of the motor-Huid from said cylinder toregulate the speed of such outflow.

20. In an elevator, the combination with a main cylinder, of a plungermovable in .said cylinder, a car connected to the upper end of saidplunger, and a throttling device wholly inclosed by said cylinder forregulating the flow of fluid from said cylinder.

2l. In an elevator, the combination of a main cylinder, fluid-flowcontrolling means, and a throttling device within said cylinder anddependent upon gravity and the friction of the outflowing fluid with apart of said throttling device to control the flow of fluid in saidcylinder.

22. In an elevator, the combination of a main cylinder, fluid-flowcontrolling means, and a throttling device wholly within said cylinderfor controlling the outflow of fluid therefrom, the operation of saidthrottling device being dependent upon gravity, fluid friction, andpressure.

23. In an elevator, the combination of a main cylinder, means whollywithin said cylinder automatically actuated by the flow of the fluid forregulating the speed of such flow, and means for'holding said regulatingmeans in normal position. v

24. Inv a plunger elevator system, the combination of the casing, aplunger vertia car on the upper end of the plunger, and a governordevice for regulating the motion of the car cont-rolled by the pressurein the casing, said governor device being mounted within the Vplungercasing, the latter being constructed and arranged to receive t-he same.

25. In a plunger elevator system, the combination of the plunger casing,a plunger vertically movable therein, a car on the upper end of theplunger, a to-and-from pipe opening into the plunger casing, and athrottling device located inside of the plunger casing and actuated byfluctuations of pressuretherein for throttling the passage of fluidthrough the to-and-from pipe.

26. In a plunger elevator system, the combination with a casing, of aplunger movable therein, a car on the upper end of the plunger, meansfor controlling the flow of fluid to and from said casing, and agovernor device within said vcasing for regulating the motion of the carby fluctuations of velocity of flow of fluid in the said casing.

27. In a hydraulic elevator, lthe combination with a main cylinder, offluid-flow controlling means, and means within said cylinder anddependent upon gravity, fluid friction and pressure to limit the speedof outflow of fluid from said cylinder.

28. In a hydraulic elevator, the combina` tion with a car and a plunger,of a cylinder for said plunger, and means within said cylinderautomatically actuated by the exhaust flow to regulate the speed ofmovement of Said plunger.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLns M. NrssnN, PAUL Dn MONTCALM.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

